1. Field of the Invention
The present invention generally relates to a clip for holding or binding documents, sheets of paper, or the like, and a driver for opening the clip so as to make the clip grasp documents or the like between grasping portions of the clip. The present invention particularly relates to a spring clip formed by an elastic single plate-like body which is bent to form a pair of grasping portions abutting against each other so that, in use, the grasping portions are opened in the directions opposite to each other so as to grasp documents or the like therebetween, and relates to a driver for driving such a spring clip to grasp documents or the like.
2. Description of the Prior Art
To bind a plurality of loose documents together, generally, a stapler, a Gem clip, or the like has been used. In a stapler, however, there has been a disadvantage in that the documents are injured because a staple accommodated in the stapler is stuck through the documents to bind them together. In the case of a Gem clip in which documents are inserted between double ring portions of the Gem clip so as to be bound together, on the other hand, there is a disadvantage in that the documents are apt to come off from the Gem clip and that the Gem clip is not suitable to clip a large number of documents together, although the Gem clip has an advantage in that the documents are not injured by the Gem clip. There has been therefore proposed a clip which is formed in such a manner that an elastic plate-like member is bent to form a pair of grasping portions abutting against each other at the extremities thereof and rotatable levers are provided outside the grasping portions so that the levers are operated by fingers to thereby open the nip between the grasping portions so as to grasp documents or the like therebetween. In the clip, however, there has been a disadvantage in that in order to bind a large number of documents together, the clip must be made large in size and the levers must be pushed with strong force to move the abutment surfaces away from each other. Such a clip is therefore unsuitable for a person whose finger force is weak. Further, the opposite side edges of the elastic plate member are arcuately outward curved so as to rotatably support the levers, and therefore if other documents are stacked on the documents bound together by this clip, there has been a possibility that the documents stacked on the documents bound together by such a clip may be injured by the curved portions of the clip.
In U.S. Pat. No. 4,332,060 patented Jun. 1, 1982, therefore, the invertor of this application has proposed a spring clip having no such levers as described above and also disclosed a driver for driving out such a spring clip. Referring to FIG. 1, the spring clip will be described. The spring clip 1 is made of an elastic plate-like metal sheet which has been bent at opposite ends of a connection portion 2 formed substantially at the central portion of the sheet so as to form a pair of grasping portions 3 with their free ends elastically abutting against each other. At the opposite edge sides of the free end of each grasping portion 3, lug portions 4 are integrally formed so as to project outward respectively. Thus, two pairs of vertically opposing lug portions 4 are formed at the free end and vertically opposite edge sides respectively so that each pair of lug portions 4 are vertically opposite to each other at each edge side at the free end of the clip 1. A slanting surface 5 is provided at the free end edge side of each grasping portion 3 including the pair of widthwise opposite lug portions 4 so that the respective slanting surfaces 5 of the pair of grasping portions 3 are made to slant in the direction to separate from each other. To bind documents or the like by use of the spring clip 1, a clip driver for opening the nip between the grasping portions 3 of the spring clip 1 is used. The clip driver has a clip accommodation portion for accommodating the spring clip 1 therein, a pair of clip opening portions fixed at the front end opposite sides of the accommodation portion respectively so that in use, the above-mentioned two pairs of lug portions 4 of the clip 1 are inserted into the clip opening portions so as to open the respective nips between the two pairs of lug portions 4 respectively, that is, open the nip between the grasping portions 3 against the elasticity of the clip 1, and a lever arranged to be slidably inserted into the accommodation portion from the rear end thereof so as to abut against the connection portion 2 of the clip 1 to thereby push the clip 1 to the clip opening portion so that the clip 1 is made to grasp documents or the like. Specifically, as shown in FIG. 2, each of the clip opening portions 6 of the clip driver is constituted by a base portion 7 and a pair of clip-opening spring portions 8. The base portion 7 has a thickness which can be inserted into the nip between the slanting surfaces 5. The pair of clip-opening spring portions 8 are extended from the front end of the base portion 7 and biased elastically in the direction so that the respective front ends of the clip-opening spring portions 8 separate from each other. The pair of clip opening portions 6 are arranged so that the nip between the slanting surfaces 5 at the above-mentioned two pairs of vertically opposite lug portions 4 of the clip 1 which are normally in contact with each other is inserted into the base portions 7. Accordingly, if the clip 1 is pressed by the lever toward the front end of the driver, into the base portions 7 the nip between the slanting surfaces 5 at the two pairs of vertically opposite lug portions 4 is inserted, and then the clip-opening spring portions 8 come into the respective nips between the two pairs of vertically opposite lug portions 4. The respective nips between the two pairs of vertically opposite lug portions 4 are opened by the spring force of the clip-opening spring portions 8 against the elasticity of the clip 1. Accordingly, a large gap is formed between the respective free ends of the grasping portions 3, and documents or the like are inserted into this gap. If the lever is further slid toward the front end of the driver in this state, the two pairs of lug portions 4 of the clip 1 are pushed out from the front ends of the clip-opening spring portions 8 respectively, so that the grasping portions 3 are urged to return to its initial state by the elasticity thereof to thereby grasp the documents therebetween.
Thus, in the conventional spring clip, the grasping portions 3 are opened by use of the lug portions 4 provided on the widthwise opposite side edges of the clip. Because the lug portions 4 are outward projected at the widthwise opposite side edges of the clip 1, however, there is a risk that documents may be often damaged by the corner portions of the lug portions 4 when the clip 1 is removed from the bound documents. On the other hand, the clip 1 is manufactured in such a manner that an elastic metal plate is first punched into a predetermined shape by means of a press and then the punched-out metal plate is subject to bending work in such a manner as described above. Accordingly, there is a possibility of occurrence of a burr on the periphery of the elastic metal plate in punch working. Such a burr not only may damage documents or the like but may injure a user per se. Accordingly, it is necessary to finish the clip 1 by grinding. It is however troublesome to finish the periphery of such small lug portions and the finishing work causes an increase in cost. There are further disadvantages in that the working with a metal mold is also troublesome because of existence of the lug portions 4 to thereby cause an increase in cost, and in that maintenance and check are also troublesome. Further, if the clip 1 is to be made of synthetic resin, the lug portions 4 must be reinforced with any material because stress is applied locally onto the lug portions 4 in opening the clip 1. Accordingly, it has been necessary to mainly use a metal plate to produce the clip 1.